1. Field of the Invention
The present invention relates to a flat display device, and ore particularly to a plasma display panel.
2. Background of the Related Art
Generally, a plasma display panel and a liquid crystal display (LCD) have lately attracted considerable attention as the most practical next generation display of flat panel displays. In particular, the plasma display panel has higher luminance and a wider visible angle than the LCD. For this reason, the plasma display panel is widely used as a thin type large display such as an outdoor advertising tower, a wall TV and a theater display.
FIG. 1a shows a structure of a related art plasma display panel of three-electrode area discharge type. As shown in FIG. 1a, the plasma display panel of three-electrode area discharge type includes an upper substrate 10 and a lower substrate 20 which are bonded opposite to each other. FIG. 1b shows a sectional structure of the plasma display panel of FIG. 1a, in which the lower substrate 20 is rotated by 90xc2x0.
The upper substrate 10 includes scan electrodes 16 and 16xe2x80x2, sustain electrodes 17 and 17xe2x80x2, a dielectric layer 11, and a passivation film 12. The scan electrodes 16 and 16xe2x80x2are formed in parallel to the sustain electrodes 17 and 17xe2x80x2. The dielectric layer 11 is deposited on the scan electrodes 16 and 16xe2x80x2 and the sustain electrodes 17 and 17xe2x80x2.
The lower substrate 20 includes an address electrode 22, a dielectric film 21 formed on an entire surface of the substrate including the address electrode 22, an isolation wall 23 formed on the dielectric film 21 between the address electrodes, and a phosphor 24 formed on surfaces of the isolation wall 23 in each discharge cell and the dielectric film 21. Inert gases such as He and Xe are mixed in a space between the upper substrate 10 and the lower substrate 20 at a pressure of 300 to 700 Torr. The space is used as a discharge area.
The scan electrodes 16 and 16xe2x80x2 and the sustain electrodes 17 and 17xe2x80x2 include transparent electrodes 16 and 17 and bus electrodes 16xe2x80x2 and 17xe2x80x2 of metal so as to increase optical transmitivity of each discharge cell, as shown in FIGS. 2a and 2b. FIG. 2a is a plane view of the sustain electrodes 17 and 17xe2x80x2 and the scan electrodes 16 and 16xe2x80x2 and FIG. 2b is a sectional view thereof.
A discharge voltage from an externally provided driving integrated circuit (IC) is applied to the bus electrodes 16xe2x80x2 and 17xe2x80x2. The discharge voltage applied to the bus electrodes 16xe2x80x2 and 17xe2x80x2 is applied to the transparent electrodes 16 and 17 to generate discharge between the adjacent transparent electrodes 16 and 17. The transparent electrodes 16 and 17 have an overall width of about 300 xcexcm and are made of indium oxide or tin oxide. The bus electrodes 16xe2x80x2 and 17xe2x80x2 are formed of either three-layered thin film of Crxe2x80x94Cuxe2x80x94Cr, or Ag. At this time, the bus electrodes 16xe2x80x2 and 17xe2x80x2 have a line width of ⅓ of a line width of the transparent electrodes 16 and 17.
The operation of the aforementioned AC plasma display panel of three-electrode area discharge type will be described with reference to FIGS. 3a to 3d. 
If a driving voltage is applied between the address electrodes and the scan electrodes, opposite discharge occurs between the address electrodes and the scan electrodes, as shown in FIG. 3a. For this reason, some electrons discharged from the inert gas in the discharge cell come into collision with a surface of the passivation film, as shown in FIG. 3b. The collision of the electrons secondarily discharges electrons from the surface of the passivation film. The secondarily discharged electrons come into collision with a plasma gas to diffuse the discharge. If the opposite discharge between the address electrodes and the scan electrodes ends, wall charges having opposite polarities occur on the surface of the passivation film on the respective address electrodes and the scan electrodes, as shown in FIG. 3c. 
If the discharge voltages having opposite polarities are continuously applied to the scan electrodes and the sustain electrodes and at the same time the driving voltage applied to the address electrodes is cut off, area discharge occurs in a discharge area on the surfaces of the dielectric layer and the passivation film due to potential difference between the scan electrodes and the sustain electrodes, as shown in FIG. 3d. The electrons in the discharge cell come into collision with the inert gas in the discharge cell due to the opposite discharge and the area discharge. As a result, the inert gas in the discharge cell is excited, and ultraviolet rays having a wavelength of 147 nm occur in the discharge cell. The ultraviolet rays come into collision with the phosphors surrounding the address electrodes and the isolation wall so that the plasma display panel is operated.
The process for fabricating the plasma display panel will be described.
As shown in FIG. 4a, an upper substrate and a lower substrate are respectively formed. As shown in FIG. 4b, the upper substrate and the lower substrate are bonded to each other and sealed along their edges. As shown in FIG. 4c, an exhaust pipe 50 is provided in the sealed substrate to exhaust air of the discharge space where the upper substrate and the lower substrate bonded to each other, so that the inert gas is implanted.
Afterwards, initial discharge is generated in the discharge cell where the inert gas is implanted, and aging process is performed to continuously discharge the discharge cell until the plasma display panel is stably operated. Tip off process is then performed to remove the exhaust pipe. Thus, the plasma display panel is completed.
To perform the aging process, an aging voltage is applied to each discharge cell. At this time, the aging voltage is higher than a normal operating voltage by 50V to 200V. Also, the greater the size of the panel is, the higher the aging voltage is.
Furthermore, as shown in FIG. 5, the aging voltage is varied depending on three phosphors of red, green and blue respectively formed in the discharge cell. Particularly, the aging voltage is the highest in the green phosphor. Thus, it is probably that insulation of the dielectric is destroyed.
The aging voltage showing red color, the aging voltage showing green color, and the aging voltage showing blue color are respectively different. Particularly, since the aging voltage showing white color is higher than the aging voltage showing the other colors, a proper voltage area for red, green, blue and white in a module becomes narrow. That is to say, if the same discharge voltage is applied to all the discharge cells, emitting time of the discharge cell having the green phosphor is later than emitting time the other discharge cells having the other colored phosphors. Accordingly, although the other phosphors are emitted, the green phosphor may not be emitted. Thus, the aging voltage showing white color should have the higher potential than that showing green color.
As described above, the related art plasma display panel has several problems.
The high aging voltage destroys insulation between the electrodes. This results in that the panel cannot be used. Also, since the redundancy of the operating voltage in the module is small, the module may be operated in error.
Accordingly, the present invention is directed to a plasma display panel that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a plasma display panel in which an aging voltage of a green cell having the highest aging voltage is lowered to prevent insulation of a dielectric from being destroyed, and deviation of the operating range of each discharge cell is reduced to increase redundancy of the operating voltage.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a plasma display panel according to the first embodiment of the present invention includes an address electrode formed in each discharge cell where a red phosphor, a green phosphor and a blue phosphor are provided, and a sustain electrode formed to cross the address electrode, having a first width in a discharge cell having the red phosphor, a second width in a discharge cell having the green phosphor, and a third width in a discharge cell having the blue phosphor.
In another aspect, a plasma display panel according to the second embodiment of the present invention includes a first address electrode formed with a first width in a discharge cell having a red phosphor, a second address electrode formed with a second width in a discharge cell having a blue phosphor, and a third address electrode formed with a third width wider than the first width and the second width in a discharge cell having a green phosphor.
In other aspect, a plasma display panel according to the third embodiment of the present invention includes a first address electrode formed with a first width in a discharge cell having a red phosphor, a second address electrode formed with a second width in a discharge cell having a blue phosphor, a line formed with a third width in a discharge cell having a green phosphor, and a plurality of third address electrodes formed with a fourth width wider than the third width on some portion of the line at certain intervals.
In still another aspect, a plasma display panel according to the fourth embodiment of the present invention includes an address electrode respectively formed in each discharge cell having a red phosphor, a green phosphor and a blue phosphor, and a dielectric film deposited on the address electrode, having a first thickness in a discharge cell having the red phosphor, a second thickness in a discharge cell having the green phosphor, and a third thickness in a discharge cell having the blue phosphor.
In further still another aspect, a plasma display panel according to the fifth embodiment of the present invention includes a first isolation wall formed between a first address electrode in a discharge cell having a red phosphor and a second address electrode in a discharge cell having a blue phosphor, a second isolation wall formed between a third address electrode in a discharge cell having a green phosphor and the first address electrode at a first interval from the first isolation wall, and a third isolation wall formed between a fourth address electrode next to the third address electrode and the third address electrode at a second interval greater than the first interval from the second isolation wall.
In further still other aspect, a plasma display panel according to the sixth embodiment of the present invention includes a first isolation wall formed between a first address electrode in a first discharge cell having a red phosphor and a second address electrode in a second discharge cell having a blue phosphor, a second isolation wall formed between a third address electrode in a third discharge cell having a green phosphor and the first address electrode so that the first discharge cell protrudes and the third discharge cell is recessed, and a third isolation wall formed between a fourth address electrode next to the third address electrode and the third address electrode.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.